Method for manufacturing high performance components

Abstract

A method for producing high performance components by the consolidation of powdered materials under conditions of hot isostatic pressure. The method uses the inclusion of reactive materials mixed into pressure-transmitting mold materials and into the powder to be consolidated to contribute to in-situ materials modification including purification, chemical transformation, and reinforcement. The method also uses encapsulation of the mold in a sealed container to retain the mold material in position, and to exclude air and contaminants.

What is claimed is: 
     
       1. A method for manufacturing high performance components, comprising the steps of: mixing a particulate material with a binder to form a mold material,   shaping said mold material into a plurality of partial molds having an external surface and an interior cavity and being of sufficient solidity to maintain a shape,   yet being compressible under pressure,   assembling said partial molds to form an integrated mold with an interior cavity,   filling said interior cavity with a powdered material to be consolidated,   placing said mold and powdered material in a container,   initially heating said mold to an elevated temperature to remove or fix undesirable gases, or to transform said powdered material partially or entirely to another material,   hermetically sealing said container under vacuum,   subsequently heating said container with said mold and said powdered material to an elevated temperature,   applying pressure to the external surface of said container sufficient to compress said container and said mold, and transfer a pressurizing force to said powdered material within said mold cavity, so as to consolidate said powdered material in said mold cavity and form an article; and removing material surrounding said article from said mold.   
     
     
       2. A method as defined in claim 1, wherein said initial heating step is carried out in a controlled atmosphere. 
     
     
       3. A method as defined in claim 1, wherein said subsequent heating step and said step of applying pressure are carried out simultaneously. 
     
     
       4. A method as defined in claim 1, wherein said initial heating step is carried out within a temperature range of about 300° C. to 2000° C. 
     
     
       5. A method as defined in claim 1, wherein said subsequent heating step is carried out at a temperature up to not more than about 1800° C. 
     
     
       6. A method as defined in claim 1, including an additional step prior to said filling step, which comprises mixing a contamination eliminating material, adapted to react with undesirable gases, with said powdered material to thereby minimize and localize contamination of said powder by said gases. 
     
     
       7. A method as defined in claim 6, wherein said contamination eliminating material comprises a reactant selected from the group consisting of sodium, potassium, yttrium, lithium, beryllium, calcium, scandium, strontium, zirconium, barium, aluminum, titanium, magnesium, manganese, silicon, carbon, copper, zinc, CaH 2 , and the rare-earths. 
     
     
       8. A method as defined in claim 1, wherein said step of forming a mold material includes mixing a contamination eliminating material, adapted to react with undesirable gases, with said particulate material and binder to thereby minimize contamination of said powder by said gases. 
     
     
       9. A method as defined in claim 8, wherein said contamination eliminating material comprises a reactant selected from the group consisting of sodium, potassium, yttrium, lithium, beryllium, calcium, scandium, strontium, zirconium, barium, aluminum, titanium, magnesium, manganese, silicon, carbon, copper, zinc, CaH 2 , and the rare-earths. 
     
     
       10. A method as defined in claim 1, including the step of adding a modifying reactant adapted to modify the chemical composition of said powder. 
     
     
       11. A method as defined in claim 10, wherein said modifying reactant comprises a reactant selected from the group consisting of hydrogen, carbon monoxide, nitrogen, carbon dioxide and oxygen. 
     
     
       12. A method as defined in claim 1, wherein the step of removing said material surrounding said article comprises the step of collapsing said mold after said consolidation is complete. 
     
     
       13. A method as defined in claim 1, further comprising the step of coating a surface of said interior cavity with a coating material prior to filling said cavity with said powdered material. 
     
     
       14. A method as defined in claim 13, wherein said coating material comprises metals, intermetallics, ceramics, diamond and their mixtures. 
     
     
       15. A method as defined in claim 14, wherein said ceramics comprise calcium phosphate. 
     
     
       16. A method as defined in claim 13, wherein said coating material is porous and said powdered material comprises individual grains of a size adapted to infiltrate the pores of said coating material. 
     
     
       17. A method as defined in claim 16 wherein said porous coating is soluable, whereupon, after consolidation is complete, said coating is dissolved, resulting in said article having a porous surface. 
     
     
       18. A method as defined in claim 16, wherein said porous infiltration results in interlocking of materials, and thus a strong bond between said consolidated powder, and said consolidated coating. 
     
     
       19. A method as defined in claim 13, wherein said coating material comprises a plurality of phases, further comprising the step of removing one phase of said coating material to produce a porous coating. 
     
     
       20. A method as defined in claim 1, further comprising the step of inserting implants before assembling said partial molds to form said integrated mold. 
     
     
       21. A method as defined in claim 1, wherein said mold material comprises a combustible material and said step of removing said material surrounding said article comprises the step of at least partially burning said mold. 
     
     
       22. A method as defined in claim 1, further comprising the step of mixing said powdered material with a liquid prior to said step of feeding said powdered material into said interior cavity. 
     
     
       23. A method as defined in claim 1, wherein said step of shaping said mold material comprises shaping said mold material by a stereolithographic process. 
     
     
       24. A method as defined in claim 1, wherein said step of shaping said mold material comprises shaping said mold material by a selective laser sintering process. 
     
     
       25. A method as defined in claim 1, wherein said step of shaping said mold material comprising shaping said mold material by a machining process. 
     
     
       26. A method as defined in claim 1, wherein said container is comprised of a material selected from the group consisting of metal, ceramic, graphite particulate, BN particulate and calcium carbonate particulate.